Prediction of Clear Cell Renal Cell Carcinoma by Integrity of Cell-free DNA in Serum
Received 29 April 2009; accepted 21 June 2009. published online 04 December 2009.
Objectives
To hypothesize that serum cell-free DNA integrity may be clinically useful for prediction of clear cell renal cell carcinoma (cRCC). The integrity of cell-free DNA released from cancer cells was different from that released from apoptotic cells.
Methods
We collected peripheral blood samples from 78 patients before surgery; among these patients, 22 with tumor, both pre- and postoperation, and 42 controls without tumor. After the column extraction of DNA, we performed conventional polymerase chain reaction using different sizes of primers (size of products: 109, 193, 397, and 456 bp) of the housekeeping gene, glyceraldehyde-3-phosphate dehydrogenase for measurement of serum cf-DNA integrity.
Results
Age and gender were not associated with cf-DNA integrity in controls (P = .136 and P = .345). Among the cRCC patients, we observed no significant association between cf-DNA integrity and gender, age, tumor grade (P = .510, P = .618 and P = .052), except tumor stage and size (P = .001 and P = .001). All specimens contained 109 bp products. The 193 bp product was detected in 75 of 78 cRCCs and 37 of 42 controls (P = .091), 21 of 22 patients preoperation and 19 of 22 postoperation (P = .294). The 397 bp product was detected in 71 of 78 cRCCs and 0 of 42 of controls (P = .001), 18 of 22 patients preoperation- and 7 of 22 postoperation (P = .003). The 456 bp product was detected in 69 of 78 of cRCCs and 0 of 42 of controls (P = .001), 18 of 22 preoperation and 3 of 22 postoperation (P = .002).
Conclusions
Serum cf-DNA integrity may be a potential tool for the detection of clear cRCC.
aDepartment of Urology, CHU of St-Etienne, University Jean-Monnet, St-Etienne, France
bClinical Immunology Laboratory, CHU of St-Etienne, University Jean-Monnet, St-Etienne, France
cDepartment of Pathology, CHU of St-Etienne, University Jean-Monnet, St-Etienne, France
Reprint requests: Feng Gang, M.D., Clinical Immunology Laboratory, CHU of St-Etienne, 42055 St-Etienne Cedex 2, France
This research was supported by the Comité de la Loire de la Ligue Contre le Cancer.
Feng Gang and Li Guorong have equally contributed to this work.
ABSTRACT